For each color, find the numbers that are covered by the color pattern grids on the number grid. For example, the green pattern covers the numbers 3 and 7. To find the code number, you have to remember the clue from the calculator: /4. So, take 37 as a number, what do you have to add to it to divide evenly by 4? You need to add 3 to make it 40… The biggest trick here is to figure out which orders the numbers go to get your door clue.
Do that with all the numbers and you have your code.